"At limit o8 tables though, it seems like I'm the only one raising PF, why is this?"
Because most low limit players are loose passive.
"is whether it's the correct approach?"
Depends on the situation, and what you hope to accomplish with the raise. Don't just raise because you have a good hand. Raising at low limits is usually either to build to pot or to knock people out of the pot to get it shorthanded.
Check out
O8poker, click on "strategy" then "preflop raising".